Can build for windows without precompiled headers...

... Requires some more wx header inclusions, a renaming of CopyFile (to avoid
colliding with a certain macro changing it to CopyFileW), and an explicit
deletion of a copy constructor and assignment (to avoid generation of
std::vector members for an incomplete type)

src/export/ExportMP2.cpp

@@ -44,6 +44,7 @@
 #include <wx/window.h>
 #include <wx/log.h>
 #include <wx/intl.h>
+#include <wx/stream.h>
 
 #include "Export.h"
 #include "../FileIO.h"